aid: horizonshield-dev
name: The HORIZ音s株式会社
description: >-
  The HORIZ音s株式会社 (The HORIZONs Co., Ltd., Hiratsuka, Kanagawa) operates HORIZON SHIELD, a buyer-side,
  agent-native fair-price verification service for Japanese construction and renovation estimates, built by a
  30-year master carpenter on the open JCCDB dataset (95,403 items, CC BY 4.0). Its flagship KIRA server at
  mcp.horizonshield.dev is a free, anonymous remote MCP server (15 tools, 5 prompts) and A2A agent that audits a
  quoted price against fair ranges, flags overcharge tactics, and issues SHA-256 receipts anchored to Bitcoin via
  OpenTimestamps; a FairPriceAttestation tool bridges to Google's AP2 Cart Mandate. Around it sit a public MCP
  Verification Gate (the family's one OpenAPI, plus MCP and A2A) that measures other people's MCP servers against
  an A2A Conduct Extension the company authors, the JIDEC append-only verification ledger with an RFC 9727
  api-catalog, the Yakumo verified-contractor directory MCP, a WebMCP intake server and a femtech source registry —
  every card JWS-signed, every surface unauthenticated by design, and paid for by buyers rather than contractors.
url: https://raw.githubusercontent.com/api-evangelist/horizonshield-dev/refs/heads/main/apis.yml
image: https://shield.the-horizons-innovation.com/horizon_shield_logo_512.png
x-type: company
x-source: harvest:a2a-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-09-19 (local-v3; was a2a-registry harvest stub)
x-identity-note: >-
  The registrable domain horizonshield.dev has no A/AAAA record on any public resolver (checked 1.1.1.1, 8.8.8.8,
  9.9.9.9 on 2026-09-19) and carries only MCP-registry and a2aregistry verification TXT records; every service runs
  on a subdomain and the company website is https://shield.the-horizons-innovation.com/ (the provider.url in its own
  agent cards). Unrelated to the cybersecurity products at horizonshield.org / horizonshield.ai, as the provider's
  own JSON-LD states.
specificationVersion: '0.20'
created: '2026-09-19'
modified: '2026-09-19'
tags:
- Construction
- Renovation
- Cost Estimation
- Fair Pricing
- Consumer Protection
- Verification
- Transparency Ledger
- Open Data
- MCP
- A2A
- AP2
- Agents
- agent-native
- Japan
apis:
- aid: horizonshield-dev:horizon-shield-kira-mcp-server
  name: HORIZON SHIELD KIRA MCP Server
  description: >-
    Remote Model Context Protocol server at https://mcp.horizonshield.dev/ (Streamable HTTP, POST only, protocol
    2025-06-18, serverInfo horizon-shield 1.0.9, listed on registry.modelcontextprotocol.io as
    dev.horizonshield/horizon-shield). Anonymous: initialize, tools/list (15 tools with inputSchema, outputSchema
    and read-only annotations) and prompts/list (5) need no key. Tools return fair min/avg/max price ranges and an
    overcharge danger threshold for 61 Japanese work categories, audit a quoted JPY price, scan estimate wording for
    known high-pressure tactics, issue SHA-256 tamper-evident receipts with a public verify URL, verify such
    receipts fail-closed, create an AP2 FairPriceAttestation (the one ledger-appending tool), and look up
    verification-passed contractors on Yakumo. Also installable as a Claude Code plugin and a Gemini CLI extension
    that connect to the same URL.
  humanURL: https://github.com/ogasurfproject-jpg/horizon-shield#readme
  baseURL: https://mcp.horizonshield.dev
  tags:
  - MCP
  - agent-native
  - Cost Estimation
  - Fair Pricing
  - AP2
  properties:
  - type: MCPServer
    url: mcp/horizonshield-dev-mcp.yml
  - type: MCPServer
    name: KIRA MCP endpoint (Streamable HTTP, POST)
    url: https://mcp.horizonshield.dev/
  - type: ToolCrosswalk
    url: mcp/horizonshield-dev-tool-crosswalk.yml
  - type: Documentation
    url: https://github.com/ogasurfproject-jpg/horizon-shield#readme
  - type: GettingStarted
    url: https://github.com/ogasurfproject-jpg/horizon-shield/blob/main/plugin/README.md
- aid: horizonshield-dev:horizon-shield-kira-a2a-agent
  name: HORIZON SHIELD KIRA A2A Agent
  description: >-
    Agent2Agent surface of the same service: a JWS-signed agent card at
    https://mcp.horizonshield.dev/.well-known/agent-card.json (protocolVersion 0.3.0 with 1.0-style
    supportedInterfaces, JSONRPC, version 1.0.0) declaring three skills — a borderless estimate-integrity audit, a
    Japan property acquisition and renovation intake routed to a licensed real-estate agent, and fail-closed
    verification of a signed integrity claim — plus the provider-authored A2A Conduct Extension disclosing who
    pays the agent (buyer; no referral, listing or success fee). message/send on the same JSON-RPC URL as the MCP
    server returned a completed Task; streaming and push notifications are declared unsupported.
  humanURL: https://shield.the-horizons-innovation.com/
  baseURL: https://mcp.horizonshield.dev
  tags:
  - A2A
  - agent-native
  - Verification
  properties:
  - type: AgentCard
    url: a2a/horizonshield-dev-a2a.yml
  - type: AgentCard
    name: A2A Agent Card (provider-hosted, JWS-signed)
    url: https://mcp.horizonshield.dev/.well-known/agent-card.json
- aid: horizonshield-dev:mcp-verification-gate-api
  name: MCP Verification Gate (MCP conduct register) API
  description: >-
    Read-only, keyless REST API at https://gate.horizonshield.dev described by an OpenAPI 3.1.0 document (25
    operations, version 0.4.7): the public register of MCP endpoints measured nightly against five stated
    conditions (speaks MCP, publishes an A2A agent card, declares who pays it, identical input gives identical
    output, the verdict is recomputable), per-endpoint history and change feeds (JSON and Atom), badges and
    embeds, the A2A Conduct Extension v1 specification, hash recomputation and NIP-01/BIP340 event verification,
    and the gate's own self-measurement. The same register is exposed over MCP (5 tools at /mcp) and A2A (/a2a),
    and consumed by the first-party npm client mcp-conduct and a GitHub Action.
  humanURL: https://shield.the-horizons-innovation.com/verify-directory/
  baseURL: https://gate.horizonshield.dev
  tags:
  - Verification
  - MCP
  - A2A
  - Transparency Ledger
  - Agents
  properties:
  - type: OpenAPI
    url: openapi/horizonshield-dev-mcp-conduct-register-openapi.json
  - type: OpenAPI
    name: MCP conduct register OpenAPI 3.1.0 (provider-hosted)
    url: https://gate.horizonshield.dev/openapi.json
  - type: APIReference
    url: https://gate.horizonshield.dev/spec
  - type: Documentation
    url: https://github.com/ogasurfproject-jpg/mcp-conduct#readme
  - type: Overlay
    url: overlays/horizonshield-dev-mcp-conduct-register-overlay.yaml
  - type: MCPServer
    name: Gate MCP endpoint (Streamable HTTP, POST)
    url: https://gate.horizonshield.dev/mcp
  - type: AgentCard
    name: Gate A2A Agent Card (provider-hosted, JWS-signed; graded in a2a/)
    url: https://gate.horizonshield.dev/.well-known/agent-card.json
  - type: ChangeLog
    name: Register state changes (Atom)
    url: https://gate.horizonshield.dev/feed.xml
- aid: horizonshield-dev:jidec-verification-ledger-api
  name: JIDEC Verification Ledger API
  description: >-
    Append-only, Bitcoin-anchored (OpenTimestamps) public ledger of the verification process at
    https://ledger.horizonshield.dev: an index of anchored entries, per-entry raw bytes and .ots proofs, citation
    resolution (/cite/{citation}), executable verification recipes (/verify/{n}), anchored verification paths and
    replay, a witness intake for third-party conduct walks, and agreement records. Discovery is an RFC 9727
    api-catalog served as application/linkset+json, an RFC 9116 security.txt, an llms.txt verification guide and a
    JWS-signed A2A card; a read-only MCP twin (4 tools) runs at https://jidec.horizonshield.dev/mcp. The service
    states it is SCITT-shaped but not a conformant SCITT transparency service.
  humanURL: https://ledger.horizonshield.dev/llms.txt
  baseURL: https://ledger.horizonshield.dev
  tags:
  - Transparency Ledger
  - Verification
  - Open Data
  - MCP
  - A2A
  properties:
  - type: APICatalog
    url: well-known/horizonshield-dev-api-catalog.json
  - type: APICatalog
    name: RFC 9727 API catalog (provider-hosted linkset)
    url: https://ledger.horizonshield.dev/.well-known/api-catalog
  - type: LLMsTxt
    url: llms/horizonshield-dev-jidec-llms.txt
  - type: Documentation
    url: https://ledger.horizonshield.dev/llms.txt
  - type: AgentCard
    name: JIDEC A2A Agent Card (provider-hosted, JWS-signed; graded in a2a/)
    url: https://ledger.horizonshield.dev/.well-known/agent-card.json
  - type: MCPServer
    name: JIDEC read-only MCP endpoint
    url: https://jidec.horizonshield.dev/mcp
- aid: horizonshield-dev:yakumo-verified-contractor-mcp
  name: Yakumo Verified-Contractor Directory MCP
  description: >-
    Remote MCP server at https://hearing.horizonshield.dev/mcp (serverInfo HORIZON SHIELD YAKUMO 2.3.1, protocol
    2025-06-18) exposing six read-only tools over the Yakumo mall, where only contractors that pass the KIRA
    fair-price audit are listed: list verified stores by area and trade, fetch a member profile by number, find a
    contractor from a free-text need, mall overview, how verification works, and check a named contractor
    (returns "not measured" rather than a judgement for non-members). Returns integrity scores and tiers, never
    prices; pending stores are returned separately; zero matches are returned as zero. Its A2A card discloses
    paid_by seller / listing_fee true — the one seller-funded surface in the family.
  humanURL: https://shield.the-horizons-innovation.com/yakumo/
  baseURL: https://hearing.horizonshield.dev/mcp
  tags:
  - MCP
  - Construction
  - Renovation
  - Verification
  properties:
  - type: MCPServer
    name: Yakumo MCP endpoint (Streamable HTTP, POST)
    url: https://hearing.horizonshield.dev/mcp
  - type: AgentCard
    name: Yakumo A2A Agent Card (provider-hosted; graded in a2a/)
    url: https://hearing.horizonshield.dev/.well-known/agent-card.json
  - type: Pricing
    url: https://shield.the-horizons-innovation.com/yakumo/plans/
- aid: horizonshield-dev:webmcp-intake-server
  name: HORIZON SHIELD WebMCP Intake Server
  description: >-
    A second public MCP endpoint at https://web.horizonshield.dev/mcp (serverInfo hs-webmcp 1.0.4, protocol
    2025-06-18; server.json published at shield.the-horizons-innovation.com/server-webmcp.json) acting as an intake
    desk for external LLMs and agents: route_request, run_full_audit (audit + tactics scan + awareness draft in
    one call), intake_estimate (bridges a homeowner quote to the internal KIRA audit and a free EHN third-party
    check), scan_tactics and draft_broadcast. All five tools are annotated read-only and idempotent.
  humanURL: https://shield.the-horizons-innovation.com/llms.txt
  baseURL: https://web.horizonshield.dev/mcp
  tags:
  - MCP
  - agent-native
  - Cost Estimation
  properties:
  - type: MCPServer
    name: WebMCP intake endpoint (Streamable HTTP, POST)
    url: https://web.horizonshield.dev/mcp
- aid: horizonshield-dev:femtech-source-registry-mcp
  name: HORIZON SHIELD Femtech Source Registry MCP
  description: >-
    A separate product line by the same company: a neutral, verifiable registry of femtech information sources
    exposed as a remote MCP server at https://femtech.horizonshield.dev/mcp (hs-femtech-mcp 0.4.1) with nine tools
    (register a source after machine checks of five conditions, list and fetch entries, third-party hash
    verification, neutral topic and product-category explainers, how-to-verify, agent card, check a source) and a
    JWS-signed A2A card at /.well-known/agent-card.json. Explicitly makes no diagnosis or efficacy claims. Source
    is public at github.com/ogasurfproject-jpg/hs-femtech-mcp.
  humanURL: https://github.com/ogasurfproject-jpg/hs-femtech-mcp
  baseURL: https://femtech.horizonshield.dev/mcp
  tags:
  - MCP
  - A2A
  - Verification
  properties:
  - type: MCPServer
    name: Femtech registry MCP endpoint
    url: https://femtech.horizonshield.dev/mcp
  - type: AgentCard
    name: Femtech registry A2A Agent Card (provider-hosted, JWS-signed; graded in a2a/)
    url: https://femtech.horizonshield.dev/.well-known/agent-card.json
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/horizonshield-dev-domain-security.yml
- type: AgenticAccess
  url: agentic-access/horizonshield-dev-agentic-access.yml
- type: Website
  url: https://shield.the-horizons-innovation.com/
- type: Documentation
  url: https://github.com/ogasurfproject-jpg/horizon-shield#readme
- type: APIReference
  url: https://gate.horizonshield.dev/openapi.json
- type: GettingStarted
  url: https://github.com/ogasurfproject-jpg/horizon-shield/blob/main/plugin/README.md
- type: GitHubOrganization
  url: https://github.com/ogasurfproject-jpg
- type: Blog
  url: https://shield.the-horizons-innovation.com/blog/
- type: Support
  url: https://shield.the-horizons-innovation.com/faq/
- type: Leadership
  url: https://shield.the-horizons-innovation.com/about-founder.html
- type: Pricing
  url: https://shield.the-horizons-innovation.com/yakumo/plans/
- type: TermsOfService
  url: https://shield.the-horizons-innovation.com/tos
- type: PrivacyPolicy
  url: https://shield.the-horizons-innovation.com/privacy
- type: LLMsTxt
  url: llms/horizonshield-dev-llms.txt
- type: LLMsTxt
  name: llms.txt (provider-hosted)
  url: https://shield.the-horizons-innovation.com/llms.txt
- type: AgentCard
  url: a2a/horizonshield-dev-a2a.yml
- type: MCPServer
  url: mcp/horizonshield-dev-mcp.yml
- type: ToolCrosswalk
  url: mcp/horizonshield-dev-tool-crosswalk.yml
- type: WellKnown
  url: well-known/horizonshield-dev-well-known.yml
- type: APICatalog
  url: well-known/horizonshield-dev-api-catalog.json
- type: SecurityTxt
  url: well-known/horizonshield-dev-security.txt
- type: Security
  url: security/horizonshield-dev-vulnerability-disclosure.yml
- type: VulnerabilityDisclosure
  url: security/horizonshield-dev-vulnerability-disclosure.yml
- type: Authentication
  url: authentication/horizonshield-dev-authentication.yml
- type: Conventions
  url: conventions/horizonshield-dev-conventions.yml
- type: ErrorCatalog
  url: errors/horizonshield-dev-problem-types.yml
- type: Lifecycle
  url: lifecycle/horizonshield-dev-lifecycle.yml
- type: ChangeLog
  url: changelog/horizonshield-dev-changelog.yml
- type: Conformance
  url: conformance/horizonshield-dev-conformance.yml
- type: Packages
  url: packages/horizonshield-dev-packages.yml
- type: SDKs
  url: packages/horizonshield-dev-packages.yml
- type: CLI
  url: cli/horizonshield-dev-cli.yml
- type: AgentSkill
  url: skills/_index.yml
- type: AgentSkill
  name: horizon-shield (provider-published SKILL.md)
  url: skills/horizonshield-dev-horizon-shield.md
- type: AgentSkill
  name: conduct-witness (provider-published SKILL.md)
  url: skills/horizonshield-dev-conduct-witness.md
- type: Plans
  url: plans/horizonshield-dev-plans-pricing.yml
- type: RateLimits
  url: rate-limits/horizonshield-dev-rate-limits.yml
- type: DataModel
  url: data-model/horizonshield-dev-data-model.yml
- type: AITransparency
  url: https://shield.the-horizons-innovation.com/index_en.html
x-enrichment:
  date: '2026-09-19'
  status: enriched
  artifacts_added: 46
  pass: local-v3